PROJECT SUMMARY/ABSTRACT Children and adolescents with neurofibromatosis type 1 (NF1) experience significant problems with social adjustment, adversely impacting quality of life across the lifespan. Social adjustment refers to the quality of the child's social relationships and their attainment of developmentally appropriate goals. Youth with NF1 also experience clinically significant impairments across a variety of neuropsychological domains including global intelligence, attention, and executive function. Despite evidence that neurocognitive weaknesses and family- systems factors contribute to worse social adjustment in other pediatric neurological populations, few studies have examined these associations in children with NF1. The broad objective of this proposal is to apply a developmental model of social competence in childhood brain disorder to identify aspects of social information processing underlying social interaction and social adjustment difficulties in youth with NF1. Social information processing encompasses domains such as executive functions and social-affective processing (i.e., theory of mind). The specific aims of this proposal are to 1) Compare youth with NF1 and healthy controls across domains of social competence; and 2) Establish associations among elements of social information processing, social interactions, and social adjustment in youth with NF1, and determine the role of family functioning in youth's social behaviors. [The proposed study will inform the development of evidence-based interventions designed to improve social interactions and social adjustment in this population, which currently do not exist.] Youth ages [10 to 15] with a diagnosis of NF1 (n = 40), healthy age-matched controls (n = 40), will be recruited from the Children's Hospital of Philadelphia. Participants will complete a brief neuropsychological battery assessing IQ, executive functioning, and theory of mind. Ratings of social interactions, relationship quality, perceived social acceptance, and family functioning will be collected from caregivers, teachers, and peers. Training goals include: 1) develop advanced knowledge in typical and atypical social and cognitive development within an ecological/developmental framework; 2) acquire expertise in the biological and genetic bases of neurological disease; 3) bolster advanced neuropsychological case conceptualization skills; and 4) enhance scientific skills related to research design, methodology, and statistical techniques. The proposed project advances the NICHD's vision, enhancing the understanding of mechanisms underlying atypical cognitive and behavioral development. A greater understanding of processes underlying psychosocial deficits in this population will allow providers to identify those at greatest risk for social difficulties, and inform novel, targeted intervention strategies aimed at improving functional and quality of life outcomes.